MUSCLES OF THE UPPER LIMB

Category Muscle Action Origin Insertion Innervation Blood Supply

Thorax Pectoralis Major Adduction (S)Medial rotation (S)

Medial part of clavicle, costal part of the sternum

Lateral lip of intertubercular sulcus of humerus

Lateral (C5,C6, C7) and Medial (C8, T1) pectoral nerves

Pectoral br of thoracoacromial a.

Pectoralis Minor Protracts scapulaElevates ribs

Coracoid process Ribs 2-5 Medial pectoral nerve (C8, T1)

Pectoral br of thoracoacromial a.

Serratus Anterior

Protracts and rotates scapula, holds scapula to thoracic wall

Upper 9 ribs Medial border of scapula

Long thoracic nerve (C5, C6, C7)

Lateral thoracic (br of axillary)

Shoulder Subscapularis Medial rotation of humerus (rot. Cuff)

Subscapular fossa Lesser tubercle of humerus

Upper and lower subscapular nerves

Subscapular a. (br of axillary)

Latissimus dorsi Extension (S)Adduction (S)Medial rotatation (S)

Thoracolumbar fascia (spinous pr of lower thoracic, lumbar vertebrae)

Floor of intertubercular sulcus

Thoracodorsal nerve (C6, C7, C8) (from posterior cord)

Thoracodorsal a. (inferior continuation of subscapular a)

Deltoid Adduction (S)Anterior fibers : flexion (S)Posterior fibers:Extension (S)

Lateral third of clavicle, the acromion, scapular spine

Deltoid tubercle on lateral surface of humerus

Axillary nerve (C5, C6) (from posterior cord)

Deltoid br of thoracoacromial a.

Supraspinatus Abduction (S)Lateral rotation (S)(rot. cuff)

Supraspinous fossa in the scapula

Greater tubercle of humerus

Suprascapula nerve (directly from upper trunk)

Suprascapular a. (br of thyrocervical a).

Infraspinatus Lateral rotation (S)(rot. cuff)

Infraspinous fossa in the scapula

Greater tubercle of humerus

Suprascapular nerve Suprascapular a.

Teres major Adduction (S)Medial rotation (S)

Inferior angle of scapula

Lesser tubercle and intertubercular groove (goes anteriorly)

Lower subscapular nerve

Subscapular a.Circumflex scapular a. (br of subscapular)

Teres minor Adduction (S)Lateral rotation(rot. cuff)

Lateral border of scapula

Greater tubercle of humerus (goes posteriorly)

Axillary nerve Subscapular a. Circumflex scapular a.

Category Muscle Action Origin Insertion Innervation Blood Supply

Anterior Arm Brachialis Most powerful flexion (E)

Anterior humerus Tuberosity of ulna Musculocutaneous nerve

Brachial a. (also radial recurrent a.)

Biceps Brachii Flexion (E)Supination Flexion (S) – only for long head

Long Hd : Supraglenoid tubercle of scapulaShort Hd : Coracoid process

Bicipital aponeurosis and tuberosity of radius

Musculocutaneous nerve

Brachial a.

Coracobrachialis Adduction (S)Flexion (S)

Medial humerus Coracoid process Musculocutaneous nerve

Brachial a.

Posterior arm Triceps Brachii Extension (E)Extension (S) – only long head

Long Hd: Infraglenoid tubercle of scapulaMedial Hd: Posterior surface of humerus inferior to spiral grooveLateral Hd : posterior humerus superior to spiral groove

Olecranon process (ulna)

Radial nerve Deep Brachial a. (br of brachial a.)

Category Muscle Action Origin Insertion Innervation Blood Supply

Anterior Forearm (Flexors)Most superficial Forearm Flexors

Brachioradialis Flexion (E) during semipronation (handshake muscle)

Lateral supracondylar ridge of humerus

Lateral aspect of the radius (styloid process of radius)

Radial nerve Radial recurrent a.

Pronator teres PronationFlexion (E)

Two heads; medial humerus and coronoid process of ulna

Midway along lateral surface of radius

Median nerve Ulnar artery

Flexor carpi radialis

Flexion (W)Abduction (W)

Medial epicondyle of humerus

Base of 2nd metacarpal

Median nerve Ulnar artery

Palmaris longus Flexion (W) Medial epicondyle of humerus

Palmar aponeurosis Median nerve Ulnar artery

Flexor carpi ulnaris

Flexion (W)Adduction (W)

Medial epicondyle of humerus (and medial olecranon process) – 2 heads!

Pisiform bone Ulnar nerve Ulnar artery

Superficial Forearm Flexors

Flexor digitorum superficialis

Flexion (W)Flexes MC-phalangeal and proximal interphalangeal joints of 4 medial fingers

Crescent shaped – medial epicondyle of humerus, coronoid process of ulna, anterior surface of radius

By four long tendons onto the middle phalanx of the 4 medial fingers (except thumb and pinky)

Ulnar nerve Ulnar artery

Category Muscle Action Origin Insertion Innervation Blood Supply

Deep Forearm Flexors

Flexor pollicis longus

Flexion of thumb Anterior surface of radius (interosseous membrane)

Base of distal phalanx of thumb

Median nerve (interosseous br)

Posterior interosseous a. (br of ulnar artery)

Flexor digitorum profundus

Flexion (W)Flexes MC-phalangeal and distal interphalangeal joints of 4 medial fingers

Proximal part of medial and anterior surface of ulna (interosseous membrane)

By four long tendons onto the distal phalanx of 4 medial fingers (passes through a slit in the tendon of flex. Digit. Sup)

Medial Part : Ulnar nerve.

Lateral Part : Median nerve(interosseous br)

Anterior interosseous a. (br of ulnar artery)

Pronator quadratus

Pronation Distal anterior surface of ulna

Distal anterior surface of radius

Median nerve (interosseous br)

Anterior interosseous a.

Posterior Forearm (Extensors)Superficial Forearm Extensors

Extensor carpi radialis longus

Extension (W)Abduction (W)

Lateral supracondylar ridge of humerus

Base of 2nd metacarpal

Radial nerve Radial a.

Extensor carpi radialis brevis

Extension (W)Abduction (W)

Lateral epicondyle of humerus

Base of 3rd metacarpal

Radial nerve (deep br)

Radial a.

Extensor digitorum

Extension (W)Extends MC-phalangeal joints for 4 medial fingers

Lateral epicondyle of humerus

Extensor expansions of 4 medial fingers

Radial nerve (Posterior interosseous br)

Interosseous recurrent & posterior interosseous aa.

Extensor digiti minimi

Extends MC-phalangeal and interphalangeal joints for pinky

Lateral epicondyle of humerus

Extensor expansion of pinky

Radial nerve (Posterior interosseous br)

Interosseous recurrent a.

Extensor carpi ulnaris

Extension (W)Adduction (W)

Lateral epicondyle of humerus

Base of 5th metacarpal

Radial nerve (Posterior interosseous br)

Ulnar a.

Category Muscle Action Origin Insertion Innervation Blood Supply

Deep Forearm Extensors

Supinator Supination Lateral epicondyle of humerus

Base of 5th metacarpal

Radial nerve (Posterior interosseous br)

Interosseous recurrent a.

Anconeus Extension (E) Lateral epicondyle of humerus

Lateral side of olecranon process

Radial nerve Interosseous recurrent a.

4 tendons that pass deep to the extensor digitorum (Wrist extensors)

Abductor pollicis longus

Abducts thumbHelps extend thumb at carpometacarpal joint

Posterior surface of ulna, radius and interosseous membrane

Base of 1st metacarpal

Radial nerve(Posterior interosseous br)

Posterior interosseous a.(br of ulnar artery)

Extensor pollicis brevis

Extends proximal phalanx of thumb at carpometacarpal joint

Posterior surface of radius and interosseous membrane

Base of proximal phalanx of thumb

Radial nerve (Posterior interosseous br)

Posterior interosseous a.

Extensor pollicis longus

Extends thumb at carpometacarpal and interphalangeal joints

Posterior surface of ulna and interosseous membrane

Base of distal phalanx of thumb

Radial nerve(Posterior interosseous br)

Posterior interosseous a.

Extensor indicis Extends 2nd digit (index finger)

Posterior surface of ulna and interosseous membrane

Extensor expansion of index finger

Radial nerve (Posterior interosseous br)

Posterior interosseous a.

Category Muscle Action Origin Insertion Innervation Blood Supply

Anterior/Posterior HandThenar Muscles Abductor

pollicis brevisAbducts thumb (helps oppose it)

Flexor retinaculum and tubercles on scaphoid and trapezium

Base of proximal phalanx of thumb

Median nerve(Recurrent br)

Radial a. (superficial palmar br)

Flexor pollicis brevis

Flexes thumb Tubercles on scaphoid and trapezium

Base of proximal phalanx of thumb

Median nerve (Recurrent br)

Radial a. (superficial palmar br)

Opponens pollicis

Draws 1st metacarpal bone laterally to oppose thumb

Tubercles on scaphoid and trapezium (and flexor retinaculum)

Lateral side of 1st metacarpal (thumb)

Median nerve (Recurrent br)

Radial a. (superficial palmar br)

Adductor pollicis

Adducts thumb towards the middle digits

Capitate and palmar surface of 2nd and 3rd metacarpals

Base of proximal phalanx of thumb

Ulnar nerve (deep br) Deep palmar arterial arch (br of radial a.)

Hypothenar muscles

Palmaris brevis Helps tense skin over hypothenar/thenar muscles

Palmar aponeurosis and flexor retinaculum

Into the dermis on the ulnar side of hand

Ulnar nerve (superficial br)

Ulnar a.

Opponens digiti minimi

Draws 5th metacarpal anteriorly and rotates it (opposition)

Hook of hamate (and flexor retinaculum)

Medial border of 5th metacarpal

Ulnar nerve (deep br) Ulnar a.

Flexor digiti minimi brevis

Flexes proximal phalanx of digit 5

Hook of hamate (and flexor retinaculum)

Proximal phalanx of pinky

Ulnar nerve (deep br) Ulnar a.

Abductor digiti minimi

Abducts digit 5 (pinky)

Pisiform Base of proximal phalanx of pinky

Ulnar nerve (deep br) Ulnar a.

Category Muscle Action Origin Insertion Innervation Blood Supply

Palmar muscles Lumbricals (4) Flex : MC-phalangeal jointsExtend : Intercarpophalangeal joints

1 & 2 : Lateral 2 tendons of flexor digitorum profundus3 & 4 : Medial 3 tendons of flexor digitorum profundus

Lateral sides of extensor expansions of digits 2-5

1 & 2 : Median nerve3 & 4 : Ulnar nerve

Superficial palmar arterial arch (br of ulnar a.)

Dorsal interossei (4)

Abduct digits (PAD) Adjacent sides of metacarpal bones

Bases of proximal phalanges AND dorsal expansions of digits 2, 3, 4

Ulnar nerve (deep br) Dorsal and palmar metacarpal a. (br of deep palmar arch of radial a.)

Palmar interossei(3)

Adduct digits (DAB)

2nd, 4th, 5th metacarpal bones

Dorsal digital expansions of digits 2, 4, 5

Ulnar nerve (deep br) Palmar metacarpal a.